Pharmacophore an International Research Journal
The dissolution of a hydrophilic polymer in water can be prevented by adding cross-links via either a physical or a chemical process. A cross-linked hydrosol is called a hydrogel and swells in the surrounding liquid to a certain swelling ratio, depending on the number of cross-links, i.e., the cross-linking density. These hydrogels have many advantageous features including, stimuli responsive, good diffusion properties, low toxicity and good compatibility, Because of their chemical structures are similar to those of the bioactive Glycosoaminoglycan (GAG) molecules present in the extra-cellular matrix. Hydrogel preparation by freeze- thaw method involves physical cross-linking due to crystallite formation. This method does not require the presence of a cross-linking agent such physically cross-linked materials also exhibit higher mechanical strength than chemical or irradiative techniques. In Physical hydrogels, mechanical load can be distributed along the crystallites of the three dimensional structures. Extent crosslinking hydrogel analyzed by FTIR and DSC. The molecular transport phenomenon, as studied by the dynamic swelling experiments.
